


Overprotective Big Brother Syndrome

by TheDarkCrimsonBlood



Category: One Piece
Genre: Adorable, Alternate Universe - No Powers, Brother-Sister Relationships, Brotherly Love, Cute, Family, Family Fluff, Fluff, Fluff and Humor, Funny, Humor, Lols, Sibling Bonding, Siblings, Teenagers
Language: English
Status: Completed
Published: 2019-12-02
Updated: 2019-12-02
Packaged: 2021-02-17 22:54:22
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,322
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21651094
Author URL: https://archiveofourown.org/users/TheDarkCrimsonBlood/pseuds/TheDarkCrimsonBlood
Summary: He couldn't help it. She was just too cute.
Relationships: Brother/Sister, Monkey D. Luffy & Portgas D. Ace, Monkey D. Luffy/Trafalgar D. Water Law
Comments: 1
Kudos: 102





	Overprotective Big Brother Syndrome

Overprotective Big Brother Syndrome

Ace was always hiding his little sister from everyone. When she was born, the first thing on his mind had been how people would try to steal her away because she was so cute. Cute with a 'K' and an extra 'u'. Kyuute. The big eyes and chubby cheeks that people always wanted to coo over made Ace want to hide her away and keep her all to himself. He didn't like other people touching her. Luffy belonged to him, and they would just have to deal with it.

It wasn't really a surprise for him, his parents, or his friends when he began dressing Luffy in male clothing. She was five years old at the time, but still so tiny and adorable that Ace knew he had to hide her. He'd tie her rapidly growing hair back behind her head in a small ponytail, and place hats on her head that were always somewhat too big for her. It never seemed to affect Luffy, rather, she seemed to enjoy getting so much attention from her big brother. Besides; Luffy never liked dresses or skirts anyway.

Luffy was a tomboy really, and that was just one of the many things he liked about her. She was never afraid to get dirty, she didn't cry easily, and she was tough. However, she always came straight to him whenever she needed him. Luffy never went to her mother or their father; she always went to him with her problems. Whenever she felt lonely, whenever she had nightmares, whenever she was hurt; she came to him. Ace was always happy to be there for her, to be her number one in the whole world. It was a great feeling.

As this tiny, tiny little thing continued to grow, Ace never found the need to bind her chest. She was naturally flat chested and he thanked every single last fucking god out there for that. He doesn't want men looking at her sister in that way, less they wanted a snapped neck. However, despite her flat chest and no figure, Luffy was cute. Luffy was always cute. She'd pout and smile and control him through any emotion she could find. Just a simple glance from her would make his heart melt as he was filled with the need to hug her. She'd eat and eat and eat, but somehow she'd never gain a pound.

In all honesty, Ace had planned on hiding Luffy for the rest of her life. It was only luck that she looked like a boy when he tied her hair up and threw clothing on her that was baggy and big; so of course, everyone either thought she was a boy or a cross-dresser. Ace was okay with that, but then when she came home from school he'd start hearing names from her. The names of her friends.

Zoro.

Usopp.

Sanji.

Franky.

They were boys.

Ace would watch from the window murderously whenever Luffy would leave with one of her friends, or invite them over. Ace hated how easily Luffy hugged them; but she'd always be a huger and that was okay with him, as long as she was hugging him. Ace hated how Zoro would play with Luffy's hair, how Usopp's face would always find it's way into Luffy's chest, how Franky would always pick her up for the strangest of reasons, and he defiantly hated how Sanji would swoon around her and constantly declared his love for her and any other woman in his wake. (Don'tTouchHerDon'tTouchHerDon'tTouchHer!)

They're all older than her.

No, that wasn't the problem.

They were all boys.

That was the problem.

Ace thinks that since they're older than her, they should know math. Yet they can't seem to figure out the simplest of equations he gives them

'You+Luffy=Death' and 'You-life=Happy Ace' and 'You+Luffy=Hell' Are equations he has to solve for them; and when he does, they always choose to put some distance in between themselves and him.

They have their first sleepover at Luffy's house. Ace uses that time to access the situation better, to discover who he has to worry about the most. He's relieved to find out that Franky sees Luffy as a younger sibling, and that Usopp already has a girlfriend. However, anything but relief floods him as he finds out both Sanji and Zoro are single. Thus, he spends the night staring at them from Luffy's closet. It's two in the morning when he's noticed for the first time; his eyes glint brightly, and the rabid drool dripping from his mouth is anything but endearing.

It's because of Ace that there is a small group of boys running out into the streets at two am in the morning.

When Luffy turns thirteen, he begins to realize that Zoro and Sanji are not the people he should be worrying about. The one Ace should be worrying about is Luffy's first crush. Ace has been hearing a lot about him; his long limbs, soft hair, and gentle voice. Luffy always plays with her hair or hides a red face when she talks about him.

Trafalgar Law.

Ace starts to catch sight of this fifteen year old boy bringing her home; sometimes he'll carry her, sometimes she'll be attached to his back as he rides his bike, and sometimes they'll hold hands. These are all actions that Ace hates to see. He let's it be though, because he simply knows something that Law doesn't.

Luffy has no sex appeal.

No curves, tiny breasts, thin lips, and no manners.

Of course, Ace hadn't exactly added puberty into this equation.

Luffy was a late bloomer; so Ace hadn't really been expecting to one day wake up on her fifteenth birthday and realize what, exactly was different. Her eyelashes had gotten longer, her hands never looked so delicate to him, her hair was softer, her lips had filled out, and she had curves. What god damned god had punished him and gave her curves? And boobs?!

Luffy's boobs weren't just any boobs either, they were big. They were so fucking big that if anyone ever wanted to talk about her boobs, they'd have to add an extra couple of 'o's so they could properly discuss how big they were! (Boooooobs!)He couldn't wrap them to make her look flat chested, and they just popped out of her old shirts!

To make things worse, by the time she was sixteen she started dressing like a girl! Shorts that clung to her knees, and shirts that would sometimes expose her chest or her stomach! She stopped tying her hair and she wore... She wore... Makeup.

Ace nearly had a heart attack when he caught her walking out of the house in a dress her friends had forced her to buy. That night, Ace clung to her leg and begged her not to leave.

Before long, Ace finds himself following Luffy and Law around on their dates. It's the small things he notices. He notices when Law walks down the road, Luffy is always away from it. He notices when Luffy gets cold he places his jacket on her. He notices that when she gets looked at perversely, he's always there to protect her and hide her from leering eyes that shouldn't be there.

Ace soon decides that he approves of their relationship; and he tells Law this after threatening to show the man a fate worse than death if he ever decides to hurt Luffy. Ace is surprised when not soon after this, Law asks for his permission to marry Luffy. Really, all he can do is say yes. Things don't get much better than Law; an aspiring doctor who only wanted to make Luffy happy.

It'll mean that Luffy will be going away, but that's okay to Ace.

'Cause Luffy will always be his little sister.

His, and and only his.

**Author's Note:**

> Imported from Fanfiction.net   
> https://www.fanfiction.net/s/10820996/1/Overprotective-Big-Brother-Syndrome  
> Thanks for reading


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